Cmr is a redox-responsive regulator of DosR that contributes to M. tuberculosis virulence.

Mycobacterium tuberculosis (MTb) is the causative agent of pulmonary tuberculosis (TB). MTb colonizes the human lung, often entering a non-replicating state before progressing to life-threatening active infections. Transcriptional reprogramming is essential for TB pathogenesis.

The proneurotrophin receptor sortilin is required for Mycobacterium tuberculosis control by macrophages.

Sorting of luminal and membrane proteins into phagosomes is critical for the immune function of this organelle. However, little is known about the mechanisms that contribute to the spatiotemporal regulation of this process. Here, we investigated the role of the proneurotrophin receptor sortilin during phagosome maturation and mycobacterial killing.

bkaR is a TetR-type repressor that controls an operon associated with branched-chain keto-acid metabolism in Mycobacteria.

This study describes how bkaR, a highly conserved mycobacterial TetR-like transcriptional repressor, regulates a number of nearby genes that have associations with branched-chain keto-acid metabolism. bkaR (MSMEG_4718) was deleted from the nonpathogenic species Mycobacterium smegmatis, and changes in global gene expression were assessed using microarray analysis and reporter gene studies. bkaR was found to directly control the expression of 10 genes in M.

Comparative investigation of the pathogenicity of three Mycobacterium tuberculosis mutants defective in the synthesis of p-hydroxybenzoic acid derivatives.

p-Hydroxybenzoic acid derivatives (p-HBADs) are glycoconjugates secreted by all Mycobacterium tuberculosis isolates whose contribution to pathogenicity remains to be determined. The pathogenicity of three transposon mutants of M. tuberculosis deficient in the biosynthesis of some or all forms of p-HBADs was studied.

The binding of mycolic acids to galectin-3: a novel interaction between a host soluble lectin and trafficking mycobacterial lipids?

Understanding the molecular mechanism of host-pathogen interactions is the basis for drug design and vaccine development. The fine composition of mycolic acids (MA), the major constituents of Mycobacterium tuberculosis (Mtb) cell envelope, as well as other cell wall-associated lipids, contribute to determine the virulence of a given strain. However, endogenous receptors for mycolic acids on susceptible cells exposed to mycobacterial infections have not been fully identified.

Therapeutic efficacy of high-dose intravenous immunoglobulin in Mycobacterium tuberculosis infection in mice.

Intravenous immunoglobulin (IVIg) is used to treat patients with primary antibody deficiencies and, at high doses, to treat a range of autoimmune and inflammatory disorders. With high-dose IVIg (hdIVIg), immunomodulatory mechanisms act on a range of cells, including T cells, B cells, and dendritic cells. Here, we demonstrate that the treatment of M.

A heterologous DNA priming-Mycobacterium bovis BCG boosting immunization strategy using mycobacterial Hsp70, Hsp65, and Apa antigens improves protection against tuberculosis in mice.

Tuberculosis is responsible for >2 million deaths a year, and the number of new cases is rising worldwide. DNA vaccination combined with Mycobacterium bovis bacillus Calmette Guerin (BCG) represents a potential strategy for prevention of this disease. Here, we used a heterologous prime-boost immunization approach using a combination of DNA plasmids and BCG in order to improve the efficacy of vaccination against Mycobacterium tuberculosis infection in mice.

Amelioration of established collagen induced arthritis by systemic IL-10 gene delivery.

A novel formulation of cationic liposomes containing the novel cytofectin ACHx was used for delivery of an anti-inflammatory cytokine gene, IL-10, to mice with established collagen induced arthritis. A single intraperitoneal injection of human IL-10 expression plasmid complexed with liposomes 2 to 4 days after the onset of arthritis was sufficient to give significant and prolonged amelioration of arthritis for 30 days. Preliminary experiments suggested that the therapeutic effect was IL-10 dose-dependent.

Human serum amyloid A has cytokine-like properties.

Human serum amyloid A (SAA) proteins are a group of 12-14 kDa apolipoproteins found predominantly in the high-density lipoprotein (HDL) fraction of plasma. Several functions have been proposed for SAA, but its primary physiological function remains elusive. In this report, we used the monocytic cell line THP-1 to investigate whether recombinant SAA1 (rSAA) or the HDL-rSAA protein complex can affect the capacity of these cells to produce inflammatory cytokines in vitro.

Analysis of the genomic and derived protein structure of a novel human serum amyloid A gene, SAA4.

We have determined the structure of the novel SAA gene, SAA4. The gene is 6.2 kb in length and comprises three introns and four exons.

Aprotinin does not inhibit the release of PGI2 or vWF from cultured human endothelial cells.

The release of prostacyclin (PGI2) and von Willebrand factor (vWF) from human umbilical vein endothelial cells (HUVEC) was examined to determine if aprotinin had any effects on these endothelial cell reactions. These end-points were chosen to indicate if this serine protease inhibitor caused alterations in the control of haemostatic function by endothelium, in the light of the improvement in haemostasis seen in patients given aprotinin therapy at the time of open heart surgery. Stimuli used to promote secretion of prostacyclin and vWF were human alpha-thrombin, histamine, protamine sulphate, poly-L-lysine and phorbol myristate acetate.

Bradykinin and ATP stimulate L-arginine uptake and nitric oxide release in vascular endothelial cells.

The effects of bradykinin and ATP on L-arginine transport and nitric oxide (NO) production were studied in porcine aortic endothelial cells cultured and perfused on microcarriers and deprived of L-arginine for 24 h. Stimulation of cells with bradykinin (100 nM) or ATP (100 microM) resulted in a rapid increase in L-arginine uptake and NO release. In the presence of nitro-L-arginine (100 microM), an inhibitor of NO synthase, the stimulatory effect of bradykinin on L-arginine uptake was partially inhibited while NO release was completely abolished.

Metabolism of adenine nucleotides in human blood.

Biologically active concentrations of potently vasoactive and platelet-active adenine nucleotides are generated in plasma by a variety of pathophysiological mechanisms. Although there is evidence that ATP and ADP are inactivated by endothelial ectonucleotidases, there has been little attempt to study the metabolic routes of their catabolism in blood or to assess the contribution of this process to their clearance in vivo. Therefore, we have studied the rates and patterns of catabolism of ATP, ADP, and AMP in whole blood, plasma, and isolated blood cells.

Kinetics of adenine nucleotide catabolism in coronary circulation of rats.

We have used the rat isolated, perfused heart to study the metabolism of adenine nucleotides on a single passage through the coronary circulation. Low doses (3-30 nmol) of ATP, ADP, or AMP injected as a bolus were extensively catabolized by ectoenzymes. Increasing doses of each nucleotide demonstrated saturability of catabolism that occurred at significantly lower doses of AMP than of ADP or ATP.

Endothelial prostacyclin release in systemic lupus erythematosus.

The ability of sera from patients with SLE to stimulate endothelial cell prostacyclin production was studied using a standardized assay system for testing the effects of serum on cultured human endothelial cell monolayers. The effects of 20 normal and 32 SLE sera on endothelial prostacyclin production were measured. No differences between the rates of prostacyclin production were seen between the two groups, either basally or when prostacyclin release was stimulated with thrombin or bradykinin.

Demonstration of plasma-membrane adenosine diphosphatase activity in rat lung.

The adenosine diphosphatase (ADPase) activity of rat lung has been investigated. Subcellular fractionation of lung tissue homogenates by sucrose density gradient centrifugation has shown the ADPase activity to be associated with the plasma membrane. ADPase was solubilised from the membranes and fractionated by ammonium sulphate precipitation to separate a specific, low-Km ADPase from non-specific alkaline phosphatase activity.

Characterization of ectonucleotidases on vascular smooth-muscle cells.

We compared the properties of the ectonucleotidases (nucleoside triphosphatase, EC 3.6.1.

Effect of a failure of energy supply on adenine nucleotide breakdown in placentae and other fetal tissues from rat and guinea pig.

The effects of ischaemia on adenylate energy charge of tissues from fetal rats and fetal guinea pigs were measured. Adult rat and guinea-pig tissues, as well as human placentae, were also studied. The largest differences observed were between the fetuses from different pregnant animals (P = 4.

Human placental mitochondrial respiration and its regulation by adenine nucleotides.

Respiratory parameters were studied in mitochondria from human placenta. Respiratory control and ADP/O ratios were low in this preparation. The adenine nucleotide content of placental mitochondria was found to be only one quarter of that found for adult uterine muscle tissue mitochondria prepared in the same way.

ATP, ADP and AMP in plasma from peripheral venous blood.

ATP, ADP and AMP in concentrations at least 1 mumol/l have been found by high pressure liquid chromatography (HPLC) in plasma from peripheral venous blood. Total adenine nucleotide concentrations of about 15-20 mumol/l can be found in some conventional clinical samples of blood using EDTA as an anticoagulant. EDTA prevented adenine nucleotide conversion to inosine in plasma.

Mechanical and metabolic viability of a placental perfusion system in vitro under oxygenated and anoxic conditions.

In vitro dual circuit perfusion of the placenta with well-oxygenated medium results in the continuous and stable consumption of oxygen and glucose over a 2-h perfusion period. This is reflected in a stable production of lactate and an energy charge which is higher at the end of the perfusion period than that seen in fresh placental tissue immediately after vaginal delivery. Anoxic perfusion causes an increase in glucose consumption which is more than twofold higher than that seen in the oxygenated perfusion, resulting finally in placental uptake of glucose not only from the maternal but also from the fetal circulation.

Ratio of the concentration of hypoxanthine to creatinine in urine from newborn infants: a possible indicator for the metabolic damage due to hypoxia.

The ratio of the urinary concentrations of the ATP metabolite, hypoxanthine, to that of creatinine was determined in normal newborn infants. An increase in this ratio reflects high hypoxanthine excretion and thus ATP breakdown. The ratio can be determined on random urine samples, thus simplifying sampling.